Here is my my proposal for rdf:XMLLiteral
1/ The datatype rdf:XMLLiteral is a sub-datatype of xsd:string.
2/ The lexical space of rdf:XMLLiteral is the set of finite-length
sequences of characters.
3/ The value space of rdf:XMLLiteral is the set of finite-length
sequences of characters.
4/ The lexical to value mapping for rdf:XMLLiteral is the identity
mapping.
5/ RDF syntaxes may define a special syntax for rdf:XMLLiteral and the
parse process for that RDF syntax may modify the surface form into some
other lexical form.
6a/ In RDF/XML, parseType literal is one of these special syntaxes and
the modification produces the canonical form.
6b/ In RDF/XML, parseType literal is one of these special syntaxes and
the modification does not change the canonical form.
I prefer 6a.
peter